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  <script>

    // 函数的声明(声明语句)
    foo()
    function foo() {
      console.log("foo函数被执行了~")
    }

    // 函数的表达式
    // console.log(message) // undefined
    // var message = "why"

    // console.log(bar)
    bar()
    var bar = function() {
      console.log("bar函数被执行了~")
    }

  </script>

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